Aircraft Engine Emissions Data Bank A comprehensive database of aircraft engine emissions certification data has been developed during the course of work carried out by the International Civil Aviation Organization (ICAO). This data and related information are available at the ICAO Aircraft Engine Exhaust Emissions Data Bank.

Greenhouse Gas Emissions from Aircraft

The United States recently submitted an information paper to the United Nation’s International Civil Aviation Organization (ICAO) that sets out a timeframe for initiating the U.S. domestic regulatory process for addressing greenhouse gas emissions from aircraft under the Clean Air Act.

Beginning the domestic regulatory process lays the groundwork for adopting the international standards currently being developed through ICAO’s Committee on Aviation and Environmental Protection (CAEP), and it responds to the D.C. District Court’s ruling requiring EPA to determine whether greenhouse gas emissions from aircraft cause or contribute to air pollution that may be reasonably anticipated to endanger public health or welfare. The information paper indicates that, under the agency’s current schedule, EPA intends to propose its findings in late April 2015, with final determinations expected in spring 2016.

EPA will follow notice and comment rulemaking procedures for this initial proposed action, providing ample opportunity for stakeholders and the public to provide input, and ensuring transparency.

2011 (PDF)(19 pp, 110k) and 2012 (PDF)(4 pp, 90K) Court Decisions deciding that section 231 (a)(2)(A) requires EPA to make an endangerment finding under the Clean Air Act, and that EPA must respond to the aircraft petition within 90 days of the 2012 court decision.

NOx Emissions from Commercial Aircraft Engines

EPA Adopts NOx Emission Standards for Aircraft Gas Turbine Engines

EPA adopted emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft. The requirements were previously adopted by the International Civil Aviation Organization (ICAO). Included in the rule are two new tiers of more stringent emission standards for oxides of nitrogen (NOx). These are referred to as Tier 6 standards and Tier 8 standards. The Tier 6 standards become effective for newly-manufactured aircraft engines beginning in 2013.

EPA is proposing to adopt emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft. The proposed requirements were either previously adopted by the International Civil Aviation Organization (ICAO), or agreed on at ICAO’s Committee on Aviation Environmental Protection (CAEP) in 2010. Included in the proposal are two new tiers of more stringent emission standards for oxides of nitrogen (NOx). These are referred to as Tier 6 (or CAEP/6) standards and Tier 8 (or CAEP/8) standards. The proposed standards would become effective for newly-manufactured aircraft engines beginning in 2013.

The Environmental Protection Agency's (EPA) Office of Transportation Air Quality (OTAQ) and the Federal Aviation Administration's (FAA) Office of Environment and Energy (AEE) are pleased to provide the organic gas speciation profile for use in emission inventories of aircraft equipped with turbofan, turbojet, and turboprop engines fueled with kerosene-based jet-A fuel. The development of this profile is the combined work of both agencies, taking into account the most recent data sets available at this time. EPA and FAA have agreed to continue further development of this speciated organic gas profile as new scientific information becomes available. Because this effort is a "living" methodology, air quality practitioners should verify that they have the most recent version of the documents (by date and version number on the cover) and associated speciated profile before preparing an emissions inventory.

Final Rule: Control
of Air Pollution from Aircraft and Aircraft Engines; Emission Standards
and Test Procedures (published November 17, 2005)

EPA is amending the existing emission standards for oxides
of nitrogen (NOx) for new commercial aircraft engines.
These standards are equivalent to the NOx emission standards
of the United Nations International Civil Aviation Organization
(ICAO), and thereby will bring United States aircraft standards
into alignment with the international standards. These standards
will go into effect on December 19, 2005
and they will apply to new aircraft engines
utilized on commercial aircraft that include small regional
jets, single-aisle aircraft, twin-aisle aircraft, and 747s and
larger aircraft.

Lead Emissions from Piston-Engine Aircraft Using Leaded Aviation Gasoline

The EPA is evaluating the impact of lead emissions from aircraft using leaded aviation gasoline in order to make a determination regarding whether aircraft lead emissions cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare. These actions are in response to petitioners’ requests, which are provided below along with the EPA responses to date. The EPA currently intends to issue a proposed finding on the question of endangerment in 2017. This proposed finding will then undergo public notice and comment. After evaluating comments on the proposal, we plan to issue a final endangerment finding in 2018. Documents and information relevant to the EPA’s ongoing evaluation and other EPA activities regarding lead in air are provided below.

Extension of Comment Period (PDF)(2 pp, 57K, published June 24, 2010) EPA extended the comment period by an additional 60 days for the “Advance Notice of Proposed Rulemaking on Lead Emissions from Piston-Engine Aircraft Using Leaded Aviation Gasoline.”

Petition from Friends of the Earth (PDF)(12 pp, 303K, October 3, 2006) This petition requests that the Administrator find that aircraft lead emissions cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare, and that EPA regulate those emissions.

In separate activities related to the National Ambient Air Quality Standards for lead, EPA finalized revisions to the ambient monitoring requirements for measuring lead in the air on December 14, 2010. These amendments expanded the nation's lead monitoring network to better assess compliance with the 2008 National Ambient Air Quality Standards for lead. EPA required the continuation of monitoring at airports emitting at least one ton of lead per year. EPA also required the states to conduct a year-long monitoring study at 15 airports that emit less than one ton per year to determine how these sources impact air quality.